After reading the Winter Cleaning question, I took a look at some old questions to see what could potentially be closed/removed. I found this proofreading question, which, being a proof-reading question, is off-topic, but did not appear to be closed. When I opened it up to vote to close, I discovered that it was locked. Aside from preventing new comments/answers/votes, what are the differences between locking and closing, and what are the reasons for choosing one action over another?
Locking a question doesn't allow anybody to comment, vote, and adding new answers to it. This is different from a closed question, as a closed question can still be voted, and commented; a closed question cannot have new answers, as a locked question.
The reasons for locking a question can be:
- The question keeps getting flame posts.
- The question keeps getting closed, and then re-opened.
- The question gets new answers that don't add anything, as similar answers have been already given.
In the first, and third, case the locked question doesn't necessarily need to be closed; in the second case, closing the question doesn't help, as it keeps getting re-opened (and then re-closed) in an infinite loop; the third case could for example apply to a CW question that already got enough answers, and who adds a new answer doesn't verify if a similar answer has been already written.